A gas turbine engine includes a low speed spool mechanically interconnecting a low pressure turbine and at least one of a fan and a prop, a high speed spool mechanically interconnecting a high pressure turbine and a high pressure compressor, and an epicyclic gear system mechanically coupled to the high speed spool. The gas turbine engine also includes a low pressure compressor mechanically coupled to the high speed spool via the epicyclic gear system. The low pressure compressor may be mechanically independent of the low speed spool. The gas turbine engine may include a plurality of motor-generators for transferring power between the high speed spool and the low pressure compressor.

An electric generator assembly for an aircraft is provided. The electric generator assembly includes: a main generator having a main rotor and a main stator, the main stator includes a first three-phase winding and a second three-phase winding, the first and second three-phase windings each configured to have a voltage induced therein by the main rotor, the first three-phase winding defining a phase shift from the second three-phase winding greater than zero degrees.

A convertiplane is described that comprises: a fuselage, having a first longitudinal axis and, in turn, comprising a nose and a tail portion; a pair of wings arranged on respective opposite sides of the fuselage, carrying respective rotors and generating a lift value; and a pair of engines operatively connected to respective rotors; each rotor comprising a mast rotatable about a second axis between a helicopter configuration and an aeroplane configuration; each rotor is interposed between the fuselage and the relative rotor along the direction of extension of the relative wing.

The present application provides a method and a system for controlling continuous low voltage ride-through and high voltage ride-through of a permanent magnet direct-driven wind turbine. The method includes: determining a transient time period during which the wind turbine is transitioned from a low voltage ride-through state to a high voltage ride-through state; controlling the wind turbine to provide, during the transient time period, a gradually increasing active current to the point of common coupling; and controlling the wind turbine to provide, during the transient time period, a reactive current to the point of common coupling according to an operation state of the wind turbine before the low voltage ride-through state.

The present disclosure relates to electrical machines and methods for cooling active elements of electrical machines. More in particular, the present disclosure relates to rotors of electrical machines. An electrical machine may for example be a generator for a direct drive wind turbine. An electrical machine comprises a rotor comprising a plurality of active rotor elements, a stator comprising a plurality of active stator elements, and an air gap separating the active rotor elements and the active stator elements. The rotor further comprises one or more rotor openings configured for letting air flow enter the electrical machine and cool the active rotor elements and/or active stator elements in response to a rotation of the rotor.

An electric machine having a hybrid insulative-conductive manifold is disclosed. In one aspect, an electric machine includes a manifold that includes an insulative plate and a conductive backplate positioned adjacent to the insulative plate. The insulative plate and the backplate define a first channel and a second channel therebetween. The electric machine also includes a prime winding and a secondary winding electrically isolated from the prime winding. The prime winding and the secondary winding are both in fluid communication with the first channel and the second channel. A terminal conductor extends through the backplate and insulative plate and is electrically coupled with the prime winding. The terminal conductor is electrically isolated from the backplate and provides cooling fluid to the prime winding and the first channel so that cooling fluid flows between the terminal conductor and the prime winding and between the terminal conductor and the first channel.

Methods, systems and apparatuses including systems and methods that can be used for operating a hydrokinetic turbine such as along one or more flow channels of a river for power generation is disclosed. The hydrokinetic turbine can be positioned within the one or more flow channels or can be shaped to form one or more flows and can be turned by the flow of the river.

An electric circuit providing a ground connection includes at least two brushes and a contact member, wherein each brush and the contact member form a sliding contact, wherein the contact member is connected to a ground potential by at least one of the sliding contacts, wherein at least two of the sliding contacts are connected to a current source adapted to provide a current through the sliding contacts.

A segment support structure for a stator of a generator for a wind turbine, wherein the segment support structure extends along a longitudinal axis and includes a casted assembly having a first pressure plate at one axial end of the segment support structure and a second pressure plate at the opposite axial end of the segment support structure, and a plurality of carrier elements extending from the first pressure plate to the second pressure plate.

An electric driven hydraulic fracking system is disclosed. A pump configuration includes the single VFD, the single shaft electric motor, and the single hydraulic pump mounted on the single pump trailer. A controller associated with the single VFD and is mounted on the single pump trailer. The controller monitors operation parameters associated with an operation of the electric driven hydraulic fracking system as each component of the electric driven hydraulic fracking system operates to determine whether the operation parameters deviate beyond a corresponding operation parameter threshold. Each of the operation parameters provides an indicator as to an operation status of a corresponding component of the electric driven hydraulic fracking system. The controller initiates corrected actions when each operation parameter deviates beyond the corresponding operation threshold. Initiating the corrected actions when each operation parameter deviates beyond the corresponding operation threshold maintains the operation of the electric driven hydraulic fracking system.